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/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.stream;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.FileRegion;
import io.netty.util.internal.ObjectUtil;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
/**
* A {@link ChunkedInput} that fetches data from a file chunk by chunk.
*
* If your operating system supports
* zero-copy file transfer
* such as {@code sendfile()}, you might want to use {@link FileRegion} instead.
*/
public class ChunkedFile implements ChunkedInput {
private final RandomAccessFile file;
private final long startOffset;
private final long endOffset;
private final int chunkSize;
private long offset;
/**
* Creates a new instance that fetches data from the specified file.
*/
public ChunkedFile(File file) throws IOException {
this(file, ChunkedStream.DEFAULT_CHUNK_SIZE);
}
/**
* Creates a new instance that fetches data from the specified file.
*
* @param chunkSize the number of bytes to fetch on each
* {@link #readChunk(ChannelHandlerContext)} call
*/
public ChunkedFile(File file, int chunkSize) throws IOException {
this(new RandomAccessFile(file, "r"), chunkSize);
}
/**
* Creates a new instance that fetches data from the specified file.
*/
public ChunkedFile(RandomAccessFile file) throws IOException {
this(file, ChunkedStream.DEFAULT_CHUNK_SIZE);
}
/**
* Creates a new instance that fetches data from the specified file.
*
* @param chunkSize the number of bytes to fetch on each
* {@link #readChunk(ChannelHandlerContext)} call
*/
public ChunkedFile(RandomAccessFile file, int chunkSize) throws IOException {
this(file, 0, file.length(), chunkSize);
}
/**
* Creates a new instance that fetches data from the specified file.
*
* @param offset the offset of the file where the transfer begins
* @param length the number of bytes to transfer
* @param chunkSize the number of bytes to fetch on each
* {@link #readChunk(ChannelHandlerContext)} call
*/
public ChunkedFile(RandomAccessFile file, long offset, long length, int chunkSize) throws IOException {
ObjectUtil.checkNotNull(file, "file");
ObjectUtil.checkPositiveOrZero(offset, "offset");
ObjectUtil.checkPositiveOrZero(length, "length");
ObjectUtil.checkPositive(chunkSize, "chunkSize");
this.file = file;
this.offset = startOffset = offset;
this.endOffset = offset + length;
this.chunkSize = chunkSize;
file.seek(offset);
}
/**
* Returns the offset in the file where the transfer began.
*/
public long startOffset() {
return startOffset;
}
/**
* Returns the offset in the file where the transfer will end.
*/
public long endOffset() {
return endOffset;
}
/**
* Returns the offset in the file where the transfer is happening currently.
*/
public long currentOffset() {
return offset;
}
@Override
public boolean isEndOfInput() throws Exception {
return !(offset < endOffset && file.getChannel().isOpen());
}
@Override
public void close() throws Exception {
file.close();
}
@Deprecated
@Override
public ByteBuf readChunk(ChannelHandlerContext ctx) throws Exception {
return readChunk(ctx.alloc());
}
@Override
public ByteBuf readChunk(ByteBufAllocator allocator) throws Exception {
long offset = this.offset;
if (offset >= endOffset) {
return null;
}
int chunkSize = (int) Math.min(this.chunkSize, endOffset - offset);
// Check if the buffer is backed by an byte array. If so we can optimize it a bit an safe a copy
ByteBuf buf = allocator.heapBuffer(chunkSize);
boolean release = true;
try {
file.readFully(buf.array(), buf.arrayOffset(), chunkSize);
buf.writerIndex(chunkSize);
this.offset = offset + chunkSize;
release = false;
return buf;
} finally {
if (release) {
buf.release();
}
}
}
@Override
public long length() {
return endOffset - startOffset;
}
@Override
public long progress() {
return offset - startOffset;
}
}